STRATEGIES FOR KEEPING YOUR HOME WARM WITHOUT GOING BROKE ON HEATING BILLS

Probably the best way to lower your heating bills—and be ready for power outages—is to equip your home with at least one secondary source of heat. If, like most people, your home is heated by a gas or electric furnace, you may be able to drastically cut your heating bills simply by installing a secondary source of heat in the main living area.

To give an example: One of my friends complained recently, as fall days began to turn chilly, that she was reluctant to turn on the furnace to heat a 1700-square-foot house, just so she could be comfortably toasty in her easy chair in the corner. My friend is often the only family member at home. Her husband frequently works long hours, and sometimes travels for work and is away for long periods. Yet once the furnace is on, it heats the whole house.

Sure, vents and butterfly valves on your ductwork can be adjusted so that most of the heat flows to a single area, and this is certainly worth doing, if you don’t mind sleeping in a cold bedroom—or actually prefer it.

Many of us suffer from such qualms at the beginning of the heating season, but most of us bite the bullet, turn on the heat to the entire house, and set the thermostat to the lowest temperature that we—or the family—can tolerate.

But if you have a secondary source of heat in the main living area of your house—where you and your family presumably spend most of your time—the thermostat can be set a lot lower.

Secondary sources of heat are most efficient where the home’s floor plan allows for the heat to be limited to a single room, usually the living room, where the family gathers.

There is little point in locating the toasty woodstove or gas fireplace in a fussy and formal living room that is seldom used and mainly for show, when the family space is really elsewhere in the house.

KEEPING HEAT WHERE YOU WANT IT

If you are considering installing a secondary source of heat, it’s good to evaluate the planned location in terms of your ability to close it off from the rest of the house. This will be especially helpful during power outages, when every BTU counts.

So you may be wondering, “What is this ‘close it off’ I speak of?”

Many modern houses have very large, cavernous rooms (sometimes with ceilings open to the second story of the house) that also open into other cavernous rooms by way of broad doorways that are six or more feet wide. Or perhaps the living room, dining room, and kitchen are all essentially one enormous open space.

Such spaces can be difficult to heat adequately. Without some means for closing off a smaller area in which a secondary heat source is located, the family is likely to spend power outages huddled next to an inefficient fireplace or other heat source, since what little heat doesn’t go up the chimney is quickly dissipated over a very large square footage.

People who own houses with these open floor plans will probably be reluctant to make structural changes to their homes—first, because such changes are likely to be rather extensive and, second, because the openness and spacious feel is one of the chief beauties of the home.

A secondary heat source for such a home—unless is it a large wood stove—is unlikely to produce substantial savings or provide really adequate heat during power outages, since any such “secondary” heat source must heat almost the entire house.

In older houses, rooms are more often discrete spaces, so that closing off your living room to heat only a single room may be as simple as hanging a door in an existing doorway—or, if you have not quite got around to that yet, in an emergency a quilt or blanket can be hung over a doorway, so as to contain heat in a single room with a secondary heat source.

In other houses of a somewhat older vintage, it may be possible to make fairly minor architectural changes to the house, such as adding a wall and door, or just hanging double doors, so as to make it possible to close off the living room or den—and do so without compromising the architectural integrity and attractiveness of the home’s floor plan.

EXAMPLES OF SECONDARY SOURCES OF HOME HEATING

There are so many possibilities for secondary sources of home heating—each available in many different forms—that it is daunting to even attempt to list them. Whichever type of heating unit you choose, save the owner’s manual.

If you are new to home ownership, one of the first things you should do is create a file folder labeled “Owner’s Manuals” and faithfully save all these materials for every new purchase. This includes not only heating units, but lawnmowers, ceiling fans, water heaters, and endless other purchases.

You will often think, “This device is so simple that I could disassemble and re-assemble the whole thing before breakfast.” And you probably could. It’s just that this is not the quickest or easiest way to change the internal light bulb.

Here are some excellent home heating sources:

Wood Stoves

Wood stoves and variations on these, such as pellet stoves, are one of the most wonderfully comfortable and practical heating methods you can choose. Wood can be fairly inexpensive to heat with (even nearly free), especially if you are able to cut and split your own firewood.

The chief problem for most people is the cost of the initial installation: The cost of the wood stove itself, along with the vent pipe and the carpentry work needed to run the vent pipe through a ceiling or exterior wall, can be high. While there are some very inexpensive small wood stoves, the cost of venting them to the outdoors can be rather of a shock. Often, the location of your wood stove is best planned so as to minimize these costs.

For example, the height of the flue pipe must extend at least four feet above the peak of your roof. Thirty feet of triple-walled insulated pipe could be required, along with insulated “thimbles” for those points at which the vent pipe passes through structural members of your house. This portion of the job can cost more than the wood stove.

In addition, most wood stoves are extremely heavy. You can’t just move them into the house and set them on the carpet, which is often supported by nothing more than plywood. If the stove is fairly small and lightweight, you can get away with locating the wood stove on a good-sized piece of concrete board. You will probably want to cover the concrete board with ceramic tile, since concrete board is ugly.

If the wood stove is near walls—that is, within about three feet of any interior wall—these nearby walls should also be covered with concrete board and tiled, to keep the heat radiating from the wood stove from causing a fire.

Plus, wood stoves are not exactly carefree. The fire must be started and the firebox tended. The fire should be “banked” (covered with ashes) to keep coals alive overnight, and the damper should be closed. Careful selection of firewood can also help in maintaining heat overnight, when no one is tending the wood stove. Ashes must be cleared away and removed, and firewood must be carried indoors and stacked. Most people with wood stoves find these chores enjoyable.

I think, when choosing a wood stove, it’s a good idea to pick one that has a flat top that can be used as a cooking surface, in case of power outages. There are, of course, many other features to choose from.

A large wood stove generates a tremendous amount of heat—likely enough heat to create a comfortable living area, even if your house has a modern open floor plan.

Vent-Free Natural Gas and Propane Heating

Vent-free gas heating units—and there are many kinds—are, hands-down, my favorite source of secondary heat. To tell you the truth, they are my favorite source of primary heat, and (in my opinion) should be considered as the primary heating method for some new construction, such as vacation homes, older homes with no existing central heating system, mobile homes, or homes in a warm climate.

If you cannot have a wood stove, either because of regulations in your area, or insurance issues, or because your home’s structure makes the installation prohibitively expensive, vent-free gas heating is a wonderful alternative. It’s also a wonderful supplement to heating with a wood stove; e.g., for bathrooms, where you would like to shut the door while you take your shower.

Here are some of the advantages of vent-free gas heating:

VENT-FREE GAS IS 99% ENERGY EFFICIENT. Heat is not lost traveling through a maze of ductwork, where it is dissipated in heating attics, basements, and crawl spaces. Heat is delivered where you want it and when you want it.

For those who would like to conserve on energy use, installing vent-free gas units in strategic locations will allow you to turn the thermostat way down. A gas fireplace in the living room will keep the whole family toasty warm, even if the thermostat is set at 55°, and is an especially good arrangement where, normally, only one person is at home during the day.

A second unit located in the bathroom will allow a 55° bathroom to be heated to 75° or 80° almost instantly. Everyone can shower in comfort and turn off the gas unit when they leave.

VENT-FREE GAS UNITS ARE RELATIVELY INEXPENSIVE TO INSTALL. These systems do not require triple-walled insulated vent pipes that must pass through the structural members of your house and four feet above the peak of your roof. They do not require ductwork. They do not (generally) require electricity to operate, although an electric blower fan is an optional installation with some models. Expense, over and above the cost of the unit itself, is limited to running gas lines to the selected location.

VENT-FREE GAS WILL HEAT YOUR HOME DURING A POWER OUTAGE. If you rely heavily on these units for heating, you will probably want a ceiling fan. Otherwise, you will find that you are heating mainly the top half of the room. But these units still do a good, if somewhat less efficient, job during power outages. A vent-free gas unit can produce up to 32,000 BTUs. Portable units that will work on the same 20-pound propane canister used by your gas grill are available.

MANY VENT-FREE GAS HEATING UNITS ARE BEAUTIFUL ADDITIONS TO YOUR HOME. Want a fireplace in your living room? You can buy a vent-free gas fireplace with a mantle. These come in different sizes. If your bathroom is large enough, you could even have a fireplace in the bathroom. Other models are designed to look like wood stoves. Wall-mounted units work well for bathrooms, or even for living areas.

MANY VENT-FREE GAS UNITS ARE THERMOSTATICALLY CONTROLLED. A gas fireplace, stove, or wall unit can be set to maintain just about any temperature you want. This may not be true of all smaller portable units. Be sure to check, if this is a desired feature.

Thermostatic controls can make such units worth considering as a substitute for central heating systems, especially in vacation cabins, mobile homes, and in warm-climate regions.

PORTABLE UNITS ARE AVAILABLE. While many gas heating units are intended to be stationary, being firmly attached to steel gas pipes, there are several types of portable units. Obviously these have many uses. They can be used to heat garages and workshops, and areas that are under construction. They can be used indoors during power outages to heat living spaces.

Some portable models run on small gas canisters, but these can be adapted to run on the same kind of 20-pound canister used for gas grills. Compact models are available that can be mounted directly on top of the 20-pound canister, so that you don’t have to purchase a hose attachment and lug around two bulky items to move your heat source.

VENT-FREE GAS CONSIDERATIONS AND CAVEATS.

Natural gas or propane. If you have natural gas, get a unit that uses natural gas; if you have propane, get a unit intended to run on propane.

Decide how many BTUs you need to heat the desired area. If you want some serious heat, go with 32,000 BTUs. The box the unit comes in should tell you approximately the area it will heat.

Provide for adequate ventilation. Read the directions carefully. Most such units should not be operated in small rooms without some degree of ventilation.

Do the installation carefully and correctly. Should you attempt to do this type of installation yourself? Many cities and counties have codes that prohibit do-it-yourself installation. In some rural areas where you will be on propane there are no such restrictions. If you have no existing propane tank, you can decide on a location for the unit and tank, assemble everything, attach a shut-off valve, and run a stub of gas line through an exterior wall, before you ever call the propane company.

These first-time installations are especially safe and relatively easy, since no propane or propane lines even exist on the premises. You are no more likely to experience a fire or explosion, at this stage, than if you were installing a new faucet.

Once the unit is assembled and the line is stubbed out through the wall, you can call the propane company, and they will set a propane tank and take care of running the line from your stub to the propane tank. This will include putting a regulator on the line and performing a line test. The line test checks all gas lines (they are mainly concerned with the ones you ran yourself) for leaks.

It is a happy event when the propane company performs a line test and tells you that your installation is “righty-tighty,” and you can turn on your unit.

If you are installing only one unit, the only gas line that you, as the homeowner, need to run is the shut off and a single piece of gas line, just long enough to pass through the exterior wall—a job that can be handled by one person with two pipe wrenches.

If you have never installed gas lines before, or if you are installing several units, involving running gas lines all over the place, you may want to go with professional installation—or at least get some help, especially if you are not familiar with running gas lines. While this job is not difficult to do or understand, it is hard, heavy, meticulous work that involves a certain amount of nervous strain.

While gas lines are just pipes that screw together with fittings like any other pipes, they are normally custom cut and threaded to the needed lengths by the company where you purchase the lines and fittings. You bring them the measurements for the various lengths of pipe you need and select the needed fittings. Such a company should be a good place to get any needed advice or to get a recommendation for a capable installer or helper. The propane company is also a good source of such advice and recommendations.

Lines that run along the exterior of the house are normally suspended by pipe hangers attached to the framing members of the house, and the same is true for gas lines running under the house.

In rural areas, where propane may be the single most common heating fuel, you are likely to find that half your neighbors know how to run gas lines, so you should have little trouble finding experienced help.

It is nice to be involved in the work, if possible. Knowing how stuff works around your home is just a comfortable feeling. As with simpler installations, the propane company will do a line test before turning on the propane. It is good to run gas lines with great care—mainly because, if the propane company tells you there is a leak somewhere, you will have much to do over again.

If you are installing the unit yourself, be sure to use joint compound intended for metal fittings on gas lines, on all threaded fittings. Handymen everywhere are smiting their foreheads and saying, “Duh!”

Keep the unit extremely clean. Vent-free gas heating units must be kept pretty darned clean, and should generally not be used in areas where there is a lot of dust, such as in a room with a clothes dryer.

All vent-free gas units should be cleaned meticulously every year, before lighting the pilot and firing them up when cold weather approaches. If you are having trouble getting the pilot to light or the unit fire up, the problem is usually dust and dirt.

Exceptions: The first time you light a brand new unit, it can take quite a long time for the gas to make the journey to the pilot, so expect to be patient, in this case. Also, you will probably have to keep the pilot button depressed for at least a short time after the pilot is lit, or it will go out. The reason for this is that the pilot will not stay lit until the thermocouple has warmed up. Allow up to a full minute. If it takes longer than that, something still needs cleaning.

Vent-free gas heating units are cleaned with compressed air, which you can buy in an aerosol can at most hardware stores. Begin by washing everything with a damp cloth. Clean the fake logs, if there are any. Clean the grille and interior metal housing. Clean the burner tube. Referring to the owner’s manual, blow compressed air into all the places it tells you to. Your unit should then light with ease and burn clean.

It may be necessary to repeat this process once or twice during the heating season, especially in dusty conditions. (You live on a gravel road.) When the pilot light goes out or the unit is “acting up,” clean it thoroughly and give it plenty of compressed air. Failure to do this can lead to much unpleasantness, and even hazard. Mainly, the unit will not burn clean and will cause your ceiling and walls to darken from “smoke” that is invisible to the naked eye, but will cause you to have to repaint the room. It is not good to breathe the fumes from such a neglected unit, either.

A gas fireplace with a remote is a mixed blessing. One caveat about thermostatic controls is that, in some models, the thermostat is in the remote. In other words, you use a remote to turn the flame on and off, and to set the thermostat. Luxurious, right? Except for when the batteries die or when the remote itself gives up the ghost and you have to buy a new remote. Also, remember that both the remote and the remote receiver require batteries, and the remote receiver may not be in the most convenient possible location.

If you love the idea of operating your gas fireplace with a remote, keep plenty of batteries on hand, and be sure to check the cost of a new remote before making a decision. (They are pricey.)

Yes, remote-operated fireplaces will work without the remote. You just have to turn them on and off manually after flipping a switch on the remote receiver. (I hope you saved the operating manual, so you can find it.) Without the remote, there is no thermostatic control of the unit.

Save the owner’s manual.

Electric Fireplaces and Space Heaters

Electric fireplaces and space heaters are, of course, useless for power outages, and most don’t put out enough heat to make any but the smallest rooms comfortable. Most electric heaters do not mention how many BTUs they generate, because to do so would be embarrassing.

Nevertheless, nearly every family seems to have several space heaters of one kind or another, because everyone finds them useful. They are nice for chilly days when it doesn’t make sense to turn on the heat, as an additional heat source in bathrooms, or for when you want to heat only one room.

Electric space heaters are not very energy efficient, but perhaps the most frustrating thing about them is that the cheaper ones tend to be almost throw-away items that last for only one heating season and have to be replaced.

On the other hand, the more expensive models are nice looking and will last for many years. This would include electric fireplaces and the electric space heaters that look like little wood stoves. The only maintenance these ever seem to require is to occasionally replace the light bulb that creates the illusion of a flame. This light bulb is located in a secret compartment accessed by a nearly invisible recessed screw. You will never in a million years figure out where it is hidden without referring to the owner’s manual. Keeping the owner’s manual in your files will also allow you to do this simple bulb replacement quickly.

Yes, these more expensive electric “fireplaces” and “stoves” are—well—more expensive. But they last so much longer that they are cheaper in the long run. Shrewd shoppers may find them on sale at the end of the heating season, and save even more.

As energy-inefficient as these heating units may be, they have many advantages: You need not be an HVAC technician to install them. You just plug them into a wall outlet. Most of them run on regular 110 volt current.

Used with ordinary common sense, electric space heaters are relatively safe—assuming your house wiring is up to code. The chief precaution to take with electric space heaters is to not use them in such a way as to overload electrical circuits. For example, it would be wise not to attempt to run two electric space heaters on the same circuit, or to run an electric space heater on a circuit that is running some other electrical appliance that pulls a lot of juice, such as a refrigerator. This is likely to throw the breaker.

It is notoriously unsafe to rely on electric space heaters to supply all your winter heating needs, unless you live in a very warm-climate area and need very little winter heating.

Nice electric space heaters, disguised as fireplaces and wood stoves, allow you to have a pretty good facsimile of a much-longed-for fireplace in a bedroom or bathroom. (Okay, I admit that a bathroom fireplace is one of my dearest fantasies.)

Save the owner’s manual.

Kerosene Heaters

With reasonable precautions, portable kerosene heaters are safe to use for indoor heating, and are especially suitable for emergency home heating during a power outage. Portable kerosene heaters can produce as much as 32,000 BTUs, although units are available in varying sizes.

Yes, it is important to take precautions against fire, by making sure that the heater is used at a safe distance from combustible materials of any kind, such as papers, curtains, and furnishings. Small children should be kept well away from such a heater, which may have surface temperatures of 320° F. to more than 500° F.

Another essential precaution when using a portable kerosene heater indoors is to ensure that the living space is adequately ventilated. In a weatherized or unventilated home, dangerous levels of harmful gasses can reach levels that pose a serious health hazard to high-risk groups, such as pregnant women, asthmatics, people with cardiovascular disease, children, and the elderly.

To prevent these harmful gasses from accumulating, make sure that the room/rooms that are being heated are adequately ventilated. The Michigan State University Extension suggests that for a heater that is rated at 9,100 BTUs per hour, a window that is 24 inches wide should be opened about one-half inch; for a heater that is rated at 20,000 BTUs per hour, a 24-inch-wide window should be opened about one inch.

Michigan State University Extension site also states that the danger from indoor pollution is greatest “on calm days when an unvented heater is used along with an unvented gas range, gas refrigerator and a gas clothes dryer; along with a vented water heater and furnace.” They further recommend that only 1-K grade (low sulfur) kerosene be used for indoor heating, stating that, “Use of 2-K grade kerosene will dramatically increase sulfur dioxide emissions. Using kerosene other than the 1-K grade may increase health risk.”

As with gas heaters, special attention should be given to what the owner’s manual has to say about ventilation.

What’s the final word on the safety of such units for indoor heating?

The National Kerosene Heater Association contends that these units are very safe when used properly, and The Consumer Product Safety Commission has twice rejected petitions asking that kerosene heaters be banned. Ultimately, the above website’s verdict is, “A gas or unvented portable kerosene heater has value for TEMPORARY use during a power failure, especially in remote areas,” and for daytime use.

Some people feel that the odor of kerosene heaters is objectionable. In my opinion, the newer models don’t “smell”—that is, you and your family will not be going around with the faint tang of kerosene clinging to your clothes. But I could be mistaken about that.

I have personally used portable kerosene heaters indoors with children around, and I feel that with proper precautions—and alert parental supervision—they are safe to use. The flame is well shielded (so no ones clothes will catch on fire), and modern units are designed with the safety feature of going out if knocked over, or even tilted very much. Check for such safety features when you purchase such a unit.

The main annoyance of kerosene heaters is that they can be messy to fill with kerosene.

Your heater should have come equipped with a large flat metal “tray” for it to sit on, so that any kerosene that gets splashed around doesn’t wind up on the carpet. It should also have come with a siphon tube, so that kerosene can be transferred from the kerosene can to the heater’s reservoir without making a huge mess. If these accessories did not come with your unit, be sure to pick them up. If your kerosene heater is making the whole family smell funny, it is probably because kerosene is getting slopped all over the place. Turn off the unit before refilling with kerosene.

Smaller kerosene units—and even pretty large ones—can be moved from room to room, as is often necessary during a power outage, with relative ease. Turn them off before attempting to move them.

Kerosene heaters are great for the garage or workshop, where there are fewer objections to possible messiness or smelliness—and where their impressive production of BTUs can be very welcome.

Obviously, before purchasing a kerosene heater, you will want to check around for your nearest source for purchasing 1-K grade kerosene. In most rural areas, one of the local gas stations will be equipped to sell kerosene. (There is a pump, just like a gas pump, off to the side of the place somewhere.) In cities and suburbs, kerosene suppliers may not be so conveniently located.

If you are depending on kerosene heat to get through a power outage, you will probably need about five gallons of kerosene to get you through two or three days. Hence, you will need a five-gallon kerosene can, and if the power outage continues you will need to refill it.

Despite these drawbacks, there is probably no other portable heating unit that will deliver up to 32,000 BTUs. And a kerosene heater that will deliver 32,000 BTUs will probably cost less than a comparable propane heater.

Save the owner’s manual, in case you need to replace parts.

Using Your Kitchen Range as a Secondary Heat Source

Your kitchen range can be a good secondary heat source during power outages.

I have been known to use the electric range to take the chill off of the house during chilly early fall days, or even on unseasonably cold summer days.

What’s there to know about this? Well, two things: An electrician friend of mine confided in me that 220 electric heat is far more efficient (costs less) than electric heat that runs on 110 voltage. So you are saving money by turning on the oven rather than turning on your 110 electric space heater.

Secondly, my electrician friend advised me to use the oven’s broiler (top) element for this purpose, rather than the bake (bottom) element. He explained that the broiler element can withstand continuous use at high temperatures without burning out; whereas the bake element won’t last as long if used in this way.

For the uninitiated: Kitchen stove elements are easily replaced. If either the bake or broil unit burns out, buy a new element and get out your socket set. As with kitchen range burners, they basically plug in. Oven elements just plug into a place you can’t see until you take off the back cover of the stove. This is often a good time to clean the oven, since you will have to stick your head in there. Unplug the stove before replacing the elements.

How the Japanese Keep Warm in Winter—the Kotatsu

Japanese homes, for the most part, lack central heat and air conditioning, and buildings typically lack insulation, double-paned windows, and storm doors—and this is true even though winters in northern Japan can be harsh.

No one knows why Japanese architecture is designed in this way. Some have speculated that the original ancient people who settled Japan came from tropical regions, with a tradition of building for tropical climates, and that building methods never adapted. Others have speculated that it is uneconomical to build heavily insulated homes in Japan due to earthquakes, which require frequent rebuilding.

Whatever the reason, the R value of the Japanese home is somewhat similar to that of your great-grandparents’ Victorian homes, which were also innocent of insulation. Some of us can still remember visiting our grandparents in such homes—where everyone huddled within three or four feet of an enormous coal stove with a raging fire in it, while all living spaces outside that circumference remained see-your-breath freezing.

How do the Japanese cope with this state of affairs? The traditional method for keeping warm in Japan is the kotatsu.

A kotatsu is a low table covered by a large heavy quilt or comforter which overhangs the sides of the table voluminously. Over the quilt-covered top surface of the table, another rigid tabletop holds the quilt in place, and provides a hard surface for eating, doing homework, playing games, and other family activities. Seating is on the floor, often in chairs with backs designed for floor-sitting.

So how does this arrangement keep you warm? The area under the table is heated. In modern Japan, usually an electric heater is affixed to the underside of the table. The family spends cold evenings sitting at the kotatsu with the bottom half of their bodies covered with the quilt and warmed by the heat under the table.

Often, since floors are likely to be cold, a quilt or pad is also placed on the floor, under this whole arrangement. It is also customary to wear a winter coat intended for indoor use, to keep the upper half of the body warm.

Have I ever tried this? Unhappily, I have never had just the right combination of furniture—or a space heater that I felt confident would work safely with such an arrangement, and that would also fit under a low table.

Westerners can, of course, purchase kotatsus already outfitted with an electric heater on the underside of the table, and the second tabletop for covering the quilt, but this is likely to involve a rather large investment in furniture, and would likely end in tears, if you tried to get you family to actually use this as a primary heating method.

On the other hand, the kotatsu may have practical Western application for the household in which only one person is home during the day, especially during time spent in sitting-down activities.

A simple and inexpensive kotatsu could be rigged up simply by covering your dining room table with your king-size comforter and tucking a small electric space heater under the table. While heat would escape under the chair legs, this arrangement could still provide welcome warmth. Or you could move your overstuffed easy chair up to the table to keep the heat from escaping. One blogger remarks that the simple kitchen-table version keeps everyone comfortable while the family waits for the wood stove to warm the house in the mornings.

What about using a kotatsu during power outages?

The kotatsu originated during the 14th century and the traditional heat source was not electricity, but a pot of charcoal. With careful planning, a charcoal-fired kotatsu could be a viable solution to keeping the family warm during power outages. Such charcoal-fired home-heating arrangements have been used in several countries, down through the ages. (It is interesting to compare the kotatsu with the Turkish brazier used for indoor heating: http://www.turkishculture.org/applied-arts/metal-artwork/braziers-142.htm.)

The same precautions that apply to portable kerosene heaters will also apply to using a charcoal-fired kotatsu indoors. Please carefully review the paragraphs in bold-face type under kerosene heaters.

Here’s what I mean by careful planning: There are several things you will need besides a low table with reasonably comfortable floor seating around it, and a king-size comforter.

First, you will need a container for burning charcoal. One photograph depicts a kotatsu that looks very much like the cast-iron humidifiers intended for use on top of wood stoves.

A cast-iron hibachi would certainly do the job. It seems to me that cast-iron Dutch oven could do the job, but it would require a lid with openings or some kind of grill over the top. I am also inclined to think that any charcoal burner would require a grill to support the charcoal out of contact with the bottom of the container (just as you have in your outdoor charcoal grill) to allow for air circulation beneath the coals.

Notice, too, that the pictured kotatsu is enclosed in a wooden framework—doubtless intended to keep feet at a safe distance. Seems like a good idea.

Another possibility for use as the kotatsu heater is to purchase an antique foot warmer of the kind intended to hold charcoal. As you can see from the images, many of these are enclosed with wood to prevent feet from being burned by direct contact with the hot metal of the unit.

Maybe you already have a suitable low table, a king-size comforter, and a cast-iron hibachi, and it is well within your carpentry capabilities to build a sort of wooden “cage” for the hibachi. Such a wooden cage could double as a kitchen step-stool.

Next, I would suggest that a charcoal burner of this kind should not be used without something fireproof to set it on. This, too, should be pretty easy to arrange: A piece of purchased concrete board cut to the desired size should do the job, and it could be made attractive as well as serviceable by tiling the top surface. In fact, such an item, if beautifully tiled and trimmed, could be a charming and practical addition to the family dining room table, when not in use during power outages—as a place to set hot food-serving dishes, to protect the tabletop. Or just store this tiled protective item under the low table.

So—you can see how various multi-purpose items around the house could be all ready to go, in the event of a power outage. Just round up the kitchen step-stool, yank the heat-proof centerpiece off the dining table and the comforter from off the bed, and assemble your kotatsu.

Ooops! Where are my briquettes? You will want to fire up a few of these outdoors, using the charcoal outdoor grill, wait for them to burn down to coals, and transfer to the hibachi (or whatever), and tuck the hibachi with cage onto the heat-proof tiled concrete board. Then spread the comforter over this whole arrangement and cuddle down.

Crack a window. You will want to be sure of good ventilation.

Ideally, you will have cut a piece of plywood to the size of the coffee-table top, so that you could place a hard surface over the comforter—a place to set plates of food and mugs of hot beverages, and to set up the Scrabble board.

While such an arrangement is far from simple, it could allow a family to weather an extended power outage in relative comfort—or at least at a level of comfort that the Japanese find acceptable.

CAVEATS: Setting up a kotatsu during a power outage may seem a lot like putting a bicycle together in the dark, but I can’t help it: I’ve always loved the concept. The need for many apparently “custom” items may also be a deal-breaker.

Ventilation—as from a partly opened window—is a necessity, especially if your home is very energy efficient (i.e., well sealed and insulated). The partial combustion of the charcoal under low-oxygen conditions could create carbon monoxide. Don’t let anyone put their head under the covers.

Be mindful of the potential fire hazard, and don’t omit any precautions, such as fire-proof floor protection and the enclosure for the heat source.

The kotatsu is not likely to work for you if you have small children who get a little rowdy around bedtime or naptime, unless they are continually supervised. The kotatsu is not a play fort.

Are you really going to do this? Probably not. But it’s something to keep in mind in case of a serious emergency, if you find yourself without other options.

Other Ways to Stay Warm During Power Outages—and Even Not During Power Outages

If you are among those folks who like to keep the thermostat set at a rather low temperature, you may find yourself hopping into a cold bed at night. If the power goes out in winter, you are almost certain to be hopping into a cold bed at night.

Many people try to solve this problem at Bed Bath and Beyond, by purchasing feather mattresses and down comforters, flannel sheets, electric blankets, and piles of quilts. You can also sleep in thermal underwear and socks. In the old days, people wore a nightcap, and I have known older people who sleep in a hooded sweatshirt to keep their heads warm.

But there’s one other strategy that you may not have thought of. Put hot rocks at the foot of your bed, underneath the covers. (Wear socks to bed, so you don’t scorch your feet.)

Here’s how I discovered this: Back when we had a wood stove, I kept the top surface decorated with a choice collection of cool-looking rocks.

One night I went to bed with badly chilled feet. I tossed and turned. The feet wouldn’t warm up. I thought of the hot rocks sitting on top of the wood stove and tucked them in at the foot of the bed. The result was heavenly!

A few hot rocks at the foot of your bed will warm the whole bed luxuriously. When one of my daughters was living in a hard-to-heat apartment at college, she used to fill empty water bottles with hot tap water and use them the same way, so there’s more than one way to do this.

A couple of years after making this discovery, I found a genuine antique foot warming stone at a garage sale and found that it worked even better.

If you’re using rocks, the kind that retain heat the longest are the heavy, dense, igneous rocks. Pieces of marble or granite will work well. A few such rocks will retain heat for about three hours, if they are about four inches in diameter. A real foot-warming stone will retain heat for up to eight hours. Mine is a soapstone slab that is about 8” X 12”, about an inch thick, and has a sturdy wire handle.

This method can be used during power outages, as long as you have some means to heat the stones: A gas oven, wood stove, or kerosene heater will work.

For warming children’s beds, the heated stones can be tucked into heavy socks before placing them at the foot of the bed under the covers. Kids should still wear socks to bed, to protect their feet.

Caution: Some kinds of stones will explode if exposed to very high temperatures. This is usually soft stones like sandstone, which may be permeated with moisture (and don’t retain heat very well anyway).

For everyday—not during power outages—heat stones in the oven to 200°-300°. Go with a lower temperature if you are nervous about scorching the mattress. My experience is that things start to scorch at around 350°. Wear fairly heavy socks to bed.